Electronic device



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ELECTRONIC DEVICE Filed Jan. 14, 1957 2 Sheets-Sheet 1 INVENTOR WILLIAM ROSS AIKEN ATTORNEY July 19, 1960 w. R. AIKEN 2,945,974

ELECTRONIC DEVICE Filed Jan. 14, 1957 2 Sheets-Sheet 2 INVENTOR WILLIAM R OSS AIKEN United States Patent ELECTRONIC DEVICE William Ross Aiken, Los Altos, Calif., assignor, by mesne assignments, to Kaiser Industries Corporation, a corporation of Nevada Filed Jan. 14, 1957, Ser. No. 633,930

8 Claims. (Cl. '31392) The present invention relates to an electron discharge device and more particularly to a cathode ray tube having a novel deflection electrode system for effecting deflection and scanning of the electron beam onto the target screen.

The instant invention contemplates a cathode ray tube structure capable of use in connection with television, radar, memory tubes, wave inspection and other uses. The electrode arrangement of the device is such that a relatively shallow or flat envelope may be utilized to house the operable components.

In its broadest aspects, the device comprises an electron beam source, a single low potential deflection element and a pair of low potential field defining elements in conjunction with a high potential image screen. Initial beam delivery, which is parallel to the screen, may be effectively deflected from a point of impingement near the bottom of the screen to a point near the top of the screen, and is achieved by impressing appropriate beam deflecting voltages across deflection elements disposed in the region of the electron gun.

It is an object of the invention to produce a cathode ray tube including a novel electron deflecting system for effecting a simple and readily achieved scanning procedure.

Another object of the invention is to produce a cathode ray tube wherein the electron deflection arrangement is capable of being housed within a relatively shallow or flat envelope.

Still another object of the invention is to produce a cathode ray tube adapted for use in connection with informational display systems which is suited for economical and simple manufacture.

Other objects and advantages will be manifest from a reading of the following description when read conjunction with the attached drawings, in which Figure 1 is a front view of the cathode ray tube with parts broken away to more clearly illustrate the features of the device,

Figure 2 is a sectional view of the cathode ray tube taken along line 22 of Figure 1, and

Figure 3 is a perspective view of a modification of the tube shown in Figures v1 and 2.

The cathode ray tube illustrated in Figures 1 and 2 contemplates the use of a single field defining element which may be electrically coupled to ground through a suitable electrical conductor. A pair of field defining elements 12 and 14 are employed wherein each may be coupled to ground through a suitable conductor as shown. The elements 12 and 14 are adapted to be substantially coextensive with opposite marginal edges of an electron sensitive target or image screen 16. A suitable phosphor coating 18 is applied to a surface of the target 16 in order that upon electron impingement thereon, the selected areas will give off light, the intensity of which is proportional to the intensity of the impinging beam. It will be readily understood that the target 16 may be comprised of a transparent material, such as glass, so

that the excited phosphor coating 18 may be viewed on the opposite side from which the coating 18 is applied.

The target 16 is coupled to any suitable source of high voltage.

A conventional electron gun 20 is provided to deliver an electron beam 22 initially along a path which is spaced from and substantially parallel with the target 16. The gun 20 may be of the conventional type such as described in detail in Radio Engineering by F. E. Terman on pages 210-213 and may further be provided with deflection electrodes 24 for effecting deflection of the electron beam 22 along paths closer to or further from the target 16 according to the manner in which they are energized. Similar deflection electrodes 26 are provided to effect deflection of the beam along the horizontal dimension. These deflection electrodes may be of the conventional type as described in Radio Engineering by F. E. Terman on pages 213-215. The electrodes 24 and 26 are energized from suitable electric generators, not shown.

It must be understood that other systems may be employed to deflect the electron beam in a direction toward the element 10. Among the other systems which may be satisfactorily employed is a deflection system as described in detail in applicants copending application Serial No. 396,120, filed December 4, 1953, now US. Patent 2,795,731. Briefly, the type of deflection system is shown in Figure 3 and employs a plurality of deflection electrodes 36 disposed generally coextensively and in parallel relationship with a marginal edge of the target of the tube. The electron beam 22 is initially delivered along a path which is substantially parallel to a marginal edge of the target 16 and the plurality of deflection electrodes 36 are selectively energized causing the beam 22 to be deflected along paths in a zone substantially parallel with a viewing surface of the target 16.

The entire assemblage may be housed within a relatively flat or shallow envelope 32 for purposes of establishing a substantially vacuum atmosphere in which the internal components may operate.

The specific cross-sectional shape of the element :10 is not deemed to be of any specific shape so long as it is small relative to the other dimensions of the tube. The element 10 may assume cross-sectional configurations other than the cylinder-like illustration shown in the drawings.

In the illustrated embodiment shown in Figures 1 and 2, the electron beam 22 is initially delivered along a path parallel with the phosphor coating 18 of the target 16. The cathode of the electron gun 20 is operated at 0 volts or ground potential while the target 16 may be maintained at substantially 10 kv. Successive deflection of the beam 22 from the point A to the point B of the target 16 is through trajectories A and B, respectively, by suitable beam deflecting voltages (0-3 kv.) impressed across the deflection electrodes 26, such deflection being in'a direction substantially normal to the surface of the target 16.

Deflection of the electron beam 22 in the horizontal dimension of the target 16 is accomplished by the deflection electrodes 24. By impressing suitable beam deflecting voltages (0-3 kv.) across the electrodes 24, the beam 22 is caused to sweep through a zone which is parallel to the surface of the target 16.

It will be readily understood that the field established by the elements 10, 12, and 14 creates forces. which tend to retard or repel any electron entering the field. Of course, this is due to the fact that the charge of the field is less than the phosphor target and therefore tends to repel or deflect the electrons. It will be further manifest that the closer the electron beam comes to the field defining element 10 the greater the concentration of repelling forces. This is graphically illustrated by the lines of force generally indicated as 34. It will be noted that in close proximity with the element the lines of force 34 are considerably more concentrated than at points more distant therefrom.

By suitable energization of the deflection electrodes 26, the electron beam 22 may be cause to travel along a path following the trajectory B' in a direction toward the element 10. As the beam 22 approaches the element 10, the repelling forces acting thereon become greater and effectively cause the beam 22 to be deflected toward the target 16. The forces established by the field presented by the element 12 serve to provide a more perpendicular beam contact angle in the selected areas of the target 16 relatively remote from the center thereof. It can be seen that by varying the voltage impressed across the deflection electrodes 26, the direction of travel of the electron beam 22 relative to the element 10 may like-wise be varied, as for example, from the trajectory as defined by the line B wherein the beam is caused to impinge upon the target 16 along one marginal portion thereof to the line A wherein the beam impinges upon the opposite marginal portion of the target 16.

The elements 12 and 14 serve to establish fields providing for a more perpendicular beam contact angle along the upper and lower marginal edge portions of the target 16. Further, the elements 12 and 14 tend to focus the electron beam 22 prior to the instant the beam impinges on the target 16.

In conclusion, it will be seen that by appropriate synchronized energization of the deflection electrodes 24 and 26, the electron beam 22 may be caused to scan all elemental areas of the phosphor material 18 and the target 16 thereby achieving a raster.

In operation of the embodiment shown in Figure 3, the presentation of a raster on the target of the tube is achieved by initially energizing the deflection plate 36 closest to the electron gun 20 whereby the beam 22 is bent and caused to travel between the elongate pair of deflection electrodes 26. The potential applied to the electrodes 26 is initially maintained constant thereby causing the beam 22 passing therebetween to travel downwardly at a constant angle with respect to the element 10 which acts to bend the beam into registration with the target. Successive energization of the plates 36 will establish a line trace across the target face. As the potential is varied across the electrodes 26, the beam will be caused to bend into registration with the target at different vertical levels due to the interaction between the forces applied to the beam by the element 10 and the electrodes 26. Manifestly, the frame scan is accomplished by synchronized energization of the electrodes 26 and the deflection plates 36.

The novel tube may accordingly be satisfactorily employed as an integral component of television receivers, radar systems, memory devices and other similar arrangements.

According to the provisions of the patent statutes, I have explained the principles and mode of operation of my invention, and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

What I claim is:

I. An electron discharge device comprising an electron sensitive target, an electron beam source for delivering a beam along a path which is at least initially substantially parallel to said target, a first deflection set operable to bend the beam to different trajectories in adjacent relation with said target, a second deflection means for bending said beam from said trajectories through angles acute and obtuse relative to the initial beam path in the direction of said target, and a third deflection means including at least a first and a second deflection member disposed between said second deflection means and said target and on opposite sides of the beam paths which occur subsequent to deflection of the beam by said second deflection means operable to apply deflecting forces to said beam to further adjust with said second deflection means the point of registration of said beam with said target.

2. An electron discharge device comprising an electron sensitive target, deflection means disposed in spaced relation with said target, an electron beam source including means for delivering a beam of electrons along a path which is at least initially in a plane substantially parallel to the plane of said target and said deflection means for deflection thereby in the direction of said target at angles acute and obtuse to said initial path, and a pair of field defining means, one of said field defining means being disposed in proximity and substantially coextensive relation with one marginal edge of said target and the other one of said field defining means being disposed in proximity and substantially coextensive relation with a second opposed marginal edge of said target to provide a field therebetween which is operative to further adjust the point of registration of the beam with said target.

3. A display tube comprising an electron sensitive target for providing a video display, a first deflection means disposed in spaced relation with said target for providing a zone therebetween having a field of variable intensities at successive distances from said deflection means, source means for delivering a beam of electrons adjacent said deflection means including beam control means operable to adjust the beam along successive paths in the direction of a correspondingly different field intensity for deflection by said field in the direction of said target at successively different levels, said different field intensities in said zone being of a value to effect deflection of the beam from said initial paths to paths which extend at angles acute and obtuse thereto and into registration with correspondingly different ones of said target levels and a second deflection means operable to sweep the beam in its delivery along each of said paths to thereby provide a raster presentation on said target.

4. A display tube comprising an electron sensitive target for providing a video display, a first deflection means disposed in spaced relation with said target for providing a zone therebetween having a field of variable intensities at successive distances from said deflection means, source means for delivering a beam of electrons adjacent said deflection means including beam control means operable to adjust the beam along successive paths in the direction of correspondingly different intensities of said field for deflection in the direction of said target for registration with correspondingly different vertical coordinates of the target, the intensity of certain portions of said field in said zone being of a value to effect deflection of the beam from its path through angles acute thereto and at other portions of said field being of a value to effect deflection of said beam from its path through an angle obtuse thereto, and a second deflection means operable to laterally adjust the point of entry of the beam into said zone to determine the horizontal coordinate of the point of registration of the beam end with said target.

5. A display tube as set forth in claim 4 which includes a third deflection means including at least a first and a second deflection member disposed between said target and said first deflection means, and on opposite sides of the beam paths which occur subsequent to deflection of the beam by said first deflection means in the direction of said target.

6. A display tube as set forth in claim 4 in which said source means includes means for delivering the beam along a marginal edge of said target, and said second deflection means comprises deflection means disposed along said marginal edge operable to provide a deflection field selectively at different increments along the length thereof to control the point of deflection of the beam therefrom and thereby the horizontal coordinate of the point of registration of the beam with the target.

7. A display tube as set forth in claim 4 in which said first deflection means comprises a single electrode member having a curved surface disposed in facing rela tion with said target, and means for coupling a fixed value potential thereto for the purpose of generating said fields of difierent intensities at different distances from the curved surface thereof.

8. An electron discharge device comprising an electron sensitive target, a first deflection means for providing a field of variable intensities at successive distances therefrom disposed in spaced relation with said target, means for delivering an electron beam along an initial path which initially extends in the direction of a zone which lies between said first deflection means and said target, a second deflection means operable to adjust the beam to different paths which, as projected, extend into said zone and into difierent intensities of said field in said zone for deflection thereby in the direction of said target at angles acute and obtuse to the initial beam path, and a third deflection means comprising at least a first and a second deflection member disposed between said first deflection means and said target and on opposite sides of the beam paths which occur subsequent to the deflection thereof by said first deflection member operative to adjust the path of the beam and the focusing thereof prior to registration with the target.

References Cited in the tile of this patent UNITED STATES PATENTS 2,193,959 Bull Mar. 19, 1940 2,449,558 Laniet et a1 Sept. 21, 1948 2,541,446 Trott Feb. 13, 1951 2,717,323 Clay Sept. '6, 1955 2,745,035 Lawrence May 8, 1956 2,795,729 Gabor June 11, 1957 2,795,731 Aiken June 11, 1957 2,824,988 Cone Feb. 25, 1958 

